Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 21 4 2017 07 31 68 75 Soudabeh Noori Department of Child Health Research, The Academic Center for Education, Culture and Research, Tehran University of Medical Sciences, Iran Jalil Kooh Paiehzadeh Department of Social Medicine, School of Medicine, Tehran University of Medical Sciences, Iran Ramin Mozafari Kermani Department of Child Health Research, The Academic Center for Education, Culture and Research, Tehran University of Medical Sciences, Iran Mohammadreza Nateghi Department of Child Health Research, The Academic Center for Education, Culture and Research, Tehran University of Medical Sciences, Iran 2017 06 17 Background and Aim: Oral habits have hazardous effects on children’s speech which are sometimes irreversible and permanent. This study was planned to assess these oral habits among children in daycare centers of Tehran, Iran. Methods: In this descriptive, cross-sectional study, 400 children were selected through multistage sampling from 16 day-care centers in Tehran, Iran, They were 24 to 72-month old. Bottle feeding, pacifier usage and digit sucking were determined. After interviewing parents, oral examination [using Paediatric oral skills package (POSO)] and doing standard Phonetic test, a questionnaire was completed for each child. Results: Sixty eight had one oral habit. The most prevalent habit was digit sucking (52.9%). The prevalence of bottle feeding, both digit sucking with bottle feeding, and pacifier habit were 38.2%, 7.3% and 1.4%, respectively. There were significant relationship between digit sucking and malocclusion (p<0.001, r=0.4) and hard palate malformationand (p<0.001, r=0.39). Besides, a significant relationship between bottle feeding and malocclusion (p<0.001, r=0.25) was conduted. Digit sucking had significant relationship with lisping, too (p<0.001, r=0.37). There was no gender priority in oral habits. Conclusion: Oral habits cause permanent structural conversion in speech producing and oral status. https://avr.tums.ac.ir/index.php/avr/article/view/495